Double telescope.



' A. KGNIG.

DOUBLE TELESCOPE.

APQLIOATION FILED APR. 28. 1908.

908,279. Patented Dec. 29, 1908.

If Q l W 9: 1 I Z mama/war I I m/vm vtmz UNITED STATES PATENT OFFICE.

ALBERT KGNIG, OF JENA, GERMANY, ASSIGNOR TO THE FIRM OF CARL ZEISS, OFJENA, GERMANY.

DOUBLE TELESCOPE.

Specification of Letters Patent.

Patented Dec. 29, 1908.

Application filed April 28, 1908. Serial No. 429,612.

To all whom it may concern:

Be it known that I, ALBERT KoNIs, a citizen of the German Empire, andresiding at Carl-Zeiss strass'e, Jena, in the Grand Duchy ofSaxe-Veimar, Germany, have invented a new and useful Double Telescope,of which the following is a specification.

The invention is an improvement on the stereo-telescope described in thePatent No. 807,713 and consisting of two single telescopes and aguiding-jacket enveloping them and fitted with openings for the entranceof the rays and for the ocular tubes, so that by moving the singletelescopes relatively to one another the distance between the exit axesmay be adapted to the interpupilary distance of the observer. A doubletelescope of that kind can without difficulty be converted into a doubletelescope with elevated entrance axes in order to enable observationsbeing made over the top of some obstacle sheltering the observer. Eachsingle telescope need only be provided with a compound objective prismsystem, so that the entrance axes are placed above the jacket in whichboth telescopes are fitted. Another way to the same result, which is notso simple, but which has the merit of dispensing with the compoundobjective prism systems, forms the object of the present invention. Ifthe fore part only of each single telescope be enveloped in thejacket-in other words. not only the ocular tube, but the entire afterpart of the telescope arranged so as to protrude through an opening initthe ocular tube can be placed at a lower level than the jacket and bythat means the elevation of the entrance axes above the exit axeseffected.

In the annexed drawing: Figure 1 is an elevation partly in section of adouble telescope constructed according to the invention. I Fig. 2 is asection of the same telescope along the line 22 of Fig. 1.

The two objective prisms Z), lying as usual in front of the objectivesa, are tightly mounted in the openings Z) at the ends of the jacket 6The erection of each image is effected by a set of Porro prisms b c d 6.These prism systems are at the same time instrumental in increasing thedistance between the entrance axes and, in addition thereto, in placingthe exit axes at a lower level than the entrance axes. The oculars f liebehind the prisms 6.

Each telescope casing 9 includes all the optical parts with theexception of the front prism Z). In the example shown both casings aresupposed to be slidable in the jacket 6 They are for this purpose fittedwith annular pieces g which tightly fit the cylindrical guiding surface6 of the jacket 6 For adjusting the distance between the telescopes, adouble screw h, engaging one and the other of the casings g with rightand left-handed threads respectively, is journaled inthe bracket 2'fixed to the jacket I2 I claim:

The combination, of a stereo-telescope having the objectives and theobjective prisms elevated above the oculars, with a jacket envelopingthe fore parts of the single telescopes and fitted with openings for theentrance of the rays and for the after parts of the single telescopesand with a uiding surface for adapting the distance between the singletelescopes to the interpupilary distance of the bser er.

ALBERT KONIG. -Witnesses:

PAUL KRUZER, FRITZ SANDER.

